Time-Place Learning in a Neotropical Stingless Bee, Trigona fulviventris Guérin (Hymenoptera: Apidae)

Abstract

Time-place learning, or spatio-temporal learning, occurs when an animal associates the time and place of an event, usually when foraging. This form of learning has been studied in a variety of organisms but seems only to occur in those species in which it is ecologically beneficial. For example, insectivorous birds have evolved more consistent time-place learning than granivorous birds because their prey may only be available during specific times (Falk et al, 1992). In contrast, when a species forages for a resource that is continuously produced, time-place learning is not adaptive (Beugnon et al, 1996). Many scavenging ants do not display time-place learning (Reichle, 1943; Dobrzanski, 1956). Thus, despite many organisms having the ability to learn locations and times, not all organisms studied are able to combine these abilities to time-place learn. Our objective was to establish whether a stingless bee, Tr?gona fulviventris Gu?rin (Hymenoptera: Apidae), has the ability to associate time and place when foraging. Frisch (reviewed by Frisch, 1967), Beling (1929, reviewed by Frisch, 1967) and Wahl (1932) found time place learning in honey bees {Apis mellifera L.) (Hymenoptera: Apidae). Beling (1929, reviewed by Frisch, 1967) trained marked honeybees to appear at feeding stations at specific times. An interesting feature of Beling's (1929) results is that bees began to appear at the feeding station 60 to 90 min prior to the training time; this anticipation of reward is a common feature in time-place learning (Breed et al, 2002). The only other bee that has been investigated for time-place learning is the stingless bee T amalthea (Olivier) (Breed et al, 2002). Individuals of this species learned the location and time that honey solution was available. They anticipated the time of the reward and on a day when there was no reward stingless bees still arrived at the bait station (Breed et al, 2002). Other studies of foraging suggest that time-place learning may occur in other species of stingless bee but did not directly test this hypothesis (e.g., Biesmeijer and Toth, 1998; Biesmeijer et al, 1998). Studies of time-place learning in ants have had mixed results. Reichle (1943) did not find evidence of time-place learning in the ant Myrmica rubra (L.) (Hymenoptera: Formicidae). Fourteen species of European ants studied by Dobrzanski (1956) also did not time-place learn. However, time-place learning has been confirmed in the ants Ectatomma ruidum (Roger) (Hymenoptera: Formicidae) (Schatz et al, 1994; Beugnon et al, 1996; Schatz et al, 1999) and Par aponer a clavata (F.) (Hymenoptera: Formicidae) (Harrison and Breed, 1987). The difference between ants with and without time-place learning is diet: only nectivorous ants have evolved time-place learning to exploit this regularly produced resource (Harrison and Breed, 1987). We tested the stingless bee T. fulviventris for the ability to time-place learn. Our purpose was to test for the capacity of time-place learning in a different stingless bee species, as well as to improve upon the Breed et al (2002) study by following marked individuals to differentiate the roles of learning and recruitment in the appearance of bees during our tests. We trained bees to a floral location at a fixed time over several days. We used two criteria to test the hypothesis of time-place learning: anticipation and appearance when no reward was present. Animals that time-place learn typically anticipate?arrive somewhat before the training time?once they have learned the time-place association. We recorded the anticipation of marked bees to test for time-place learning. In addition, we recorded the presence or absence of the marked bees on a day when food was not presented at the expected time.